Free at last, the iPhone 6 and iPhone 6 Plus are free at last of carrier restrictions. Just as 9to5Mac’s Mark Gurman reported on Monday, Apple is now selling fully unlocked, SIM-free iPhone 6 and iPhone 6 Plus models on its website and in retail stores. Although before you could buy an unlocked iPhone 6 from T-Mobile, those devices did come with T-Mobile SIM cards. With the option to get a SIM …